Base rnd, each side: Multiple of 14 + 13 + corner sts.
Begin 4 sts to left of corner st.
Rnd 1: Ch 1, sc in same st, *skip 2 sts, 5 dc in next st, skip 2 sts, sc in next st, skip 3 sts, [7 tr in next st, skip 3 sts, sc in next st, skip 2 sts, 5 dc in next st, skip 2 sts, sc in next st, skip 3 sts] to corner st, 9 tr in corner st, skip 3 sts, sc in next st; rep from * around, omitting last sc, join with slip st to first sc. Fasten off.